About the book (from Wikipedia):
My Uncle Oswald is a 1979 adult novel written by Roald Dahl.
The novel stars Uncle Oswald, a character who previously appeared in “The Visitor” and “Bitch”, two short stories also written by Roald Dahl (and which can both be found in the 1974 book Switch Bitch).
When Uncle Oswald discovers the sexually invigorating properties of the “Sudanese Blister Beetle”‘, he devises a plan to steal the semen of great men and sell it to women who want to have children fathered by geniuses.